package com.jushu.storbox.handler;

import java.io.File;
import java.io.FileOutputStream;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.io.Writer;
import java.lang.Thread.UncaughtExceptionHandler;
import java.lang.reflect.Field;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;

import android.content.Context;
import android.content.pm.PackageInfo;
import android.content.pm.PackageManager;
import android.content.pm.PackageManager.NameNotFoundException;
import android.os.Build;
import android.os.Environment;
import android.os.Looper;
import android.util.Log;

public class CrashHandler implements UncaughtExceptionHandler
{
    
    public static final String TAG = "CrashHandler";
    
    private Thread.UncaughtExceptionHandler mDefaultHandler;
    
    private static CrashHandler INSTANCE = new CrashHandler();
    
    private Context mContext;
    
    private Map<String, String> infos = new HashMap<String, String>();
    
    private DateFormat formatter = new SimpleDateFormat("yyyy-MM-dd-HH-mm-ss");
    
    private CrashHandler()
    {
    }
    
    public static CrashHandler getInstance()
    {
        return INSTANCE;
    }
    
    /**
     * @param context
     */
    public void init(Context context)
    {
        mContext = context;
        mDefaultHandler = Thread.getDefaultUncaughtExceptionHandler();
        Thread.setDefaultUncaughtExceptionHandler(this);
    }
    
    @Override
    public void uncaughtException(Thread thread, Throwable ex)
    {
        if (!handleException(ex) && mDefaultHandler != null)
        {
            mDefaultHandler.uncaughtException(thread, ex);
        }
        else
        {
            try
            {
                Thread.sleep(3000);
            }
            catch (InterruptedException e)
            {
                Log.e(TAG, "error : ", e);
            }
        }
    }
    
    /**
     * @param ex
     * @return 
     */
    private boolean handleException(Throwable ex)
    {
        if (ex == null)
        {
            return false;
        }
        new Thread()
        {
            @Override
            public void run()
            {
                Looper.prepare();
                Looper.loop();
            }
        }.start();
        collectDeviceInfo(mContext);
        saveCrashInfo2File(ex);
        return true;
    }
    
    /**
     * @param ctx
     */
    public void collectDeviceInfo(Context ctx)
    {
        try
        {
            PackageManager pm = ctx.getPackageManager();
            PackageInfo pi = pm.getPackageInfo(ctx.getPackageName(), PackageManager.GET_ACTIVITIES);
            if (pi != null)
            {
                String versionName = pi.versionName == null ? "null" : pi.versionName;
                String versionCode = pi.versionCode + "";
                infos.put("versionName", versionName);
                infos.put("versionCode", versionCode);
            }
        }
        catch (NameNotFoundException e)
        {
            Log.e(TAG, "an error occured when collect package info", e);
        }
        Field[] fields = Build.class.getDeclaredFields();
        for (Field field : fields)
        {
            try
            {
                field.setAccessible(true);
                infos.put(field.getName(), field.get(null).toString());
                Log.d(TAG, field.getName() + " : " + field.get(null));
            }
            catch (Exception e)
            {
                Log.e(TAG, "an error occured when collect crash info", e);
            }
        }
    }
    
    /**
     * @param ex
     * @return
     */
    private String saveCrashInfo2File(Throwable ex)
    {
        
        StringBuffer sb = new StringBuffer();
        for (Map.Entry<String, String> entry : infos.entrySet())
        {
            String key = entry.getKey();
            String value = entry.getValue();
            sb.append(key + "=" + value + "\n");
        }
        
        Writer writer = new StringWriter();
        PrintWriter printWriter = new PrintWriter(writer);
        ex.printStackTrace(printWriter);
        Throwable cause = ex.getCause();
        while (cause != null)
        {
            cause.printStackTrace(printWriter);
            cause = cause.getCause();
        }
        if (null != printWriter) {
        	printWriter.close();
        }
        String result = writer.toString();
        sb.append(result);
        try
        {
            long timestamp = System.currentTimeMillis();
            String time = formatter.format(new Date());
            String fileName = "crash-" + time + "-" + timestamp + ".log";
            if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED))
            {
                String path = Environment.getExternalStorageDirectory() + "//CloudDrive//log//";
                File dir = new File(path);
                if (!dir.exists())
                {
                    dir.mkdirs();
                }
                FileOutputStream fos = null;
                try {
                	fos = new FileOutputStream(path + fileName);
                	fos.write(sb.toString().getBytes());
				} catch (Exception e) {
					// TODO: handle exception
					e.printStackTrace();
				} finally {
					if (null != fos) {
						fos.close();
					}
				}
            }
            return fileName;
        }
        catch (Exception e)
        {
            Log.e(TAG, "an error occured while writing file...", e);
        }
        return null;
    }
}
